Biomass from microalgae separation by electroflotation with iron and aluminum spiral electrodes

•Electroflotation for separation of microalgal biomass was applicate.•Spiral-shaped electrode using aluminum and iron tubes was tested.•The impact of metal electrodes on the effluent contamination was measurement.•The best condition achieved was of 3 A/20 min, for aluminum electrode.•Concentration of iron and aluminum ions in the treated wastewater was significant.

The aim of this study was to evaluate the biomass separation of the microalgae Desmodesmus subspicatus by electroflotation with a spiral-shaped electrode using aluminum or iron tubes and to identify the metal contamination present in the effluent and biomass. Both time and electric current were controlled in the experiments. The most effective conditions for this experiment involved the use of an iron electrode for 30 min with a current of 3 A, whereas the aluminum electrode has been used effectively for 20 min with a current of 3 A. The contribution of the electroflotation system to the concentration of iron or aluminum ions in the treated wastewater is significant, and the use of the iron electrode may be less detrimental to human and animal health due to the lower toxicity remaining concentration in the effluent.